June 25, 2009

EIN GEDI, Israel – Eli Raz was peering into a narrow hole in the Dead Sea shore when the earth opened up and swallowed him. Fearing he would never be found alive in the 30-foot- deep pit, he scribbled his will on an old postcard.
After 14 hours a search party pulled him from the hole unhurt, and five years later the 69-year-old geologist is working to save others from a similar fate, leading an effort to map the sinkholes that are spreading on the banks of the fabled saltwater lake.
These underground craters can open up in an instant, sucking in whatever lies above and leaving the surrounding area looking like an earthquake zone.
The phenomenon, Raz said, stems from a dire water shortage, compounded in recent years by tourism and chemical industries as well as a growing population. "This is the most remarkable evidence of the brutal interference of humans in the Dead Sea," he said.
. . .

June 13, 2009

People who have trouble understanding and accepting this concept are taking it all way, way too literally: they think that one day some fish just decided grow legs and crawl up onto land and that that very act made them a new animal; they think that one day a bird hatched from a dinosaur egg, or that a monkey gave birth to a human.
These are also the people who have trouble understanding their own religions because they take those too literally as well.

June 11, 2009

Today, Ori Lahav and his mates at the Israel Institute of Technology, in Haifa, say that they've created the sonic equivalent of a black hole in a BEC. That's some achievement, given that physicists have wondered about this possibility for some 30 years, and various groups with the ability to create BECs have been racing to create acoustic black holes.

The general idea is to set up a supersonic flow of atoms within the BEC. Sound waves moving against this flow can never make any ground. So the region where the flow changes from subsonic to supersonic is an event horizon. Any sound waves (or phonons) created inside the event horizon can never escape because the flow there is supersonic. That's the black hole.

Lahav and co set up a supersonic flow by creating a deep potential well in the middle of a BEC that attracts atoms. The atoms stream into it but cannot give up their energy when they arrive (they're already in their lowest energy state), and so they stream across the well at supersonic speed.

The result is a region within the BEC in which the atoms move at supersonic speed. This is the black hole: any phonon unlucky enough to stray into this region cannot escape.

June 10, 2009

But there are some notable exceptions. And to be clear, by "ineffective" I mean they perform no better than a placebo. I expect this research will be used as part of the government's plan to pay for the most effective and most cost-effective treatments with our upcoming public health plan.

BETHESDA, Md. – Ten years ago the government set out to test herbal and other alternative health remedies to find the ones that work. After spending $2.5 billion, the disappointing answer seems to be that almost none of them do.

Echinacea for colds. Ginkgo biloba for memory. Glucosamine and chondroitin for arthritis. Black cohosh for menopausal hot flashes. Saw palmetto for prostate problems. Shark cartilage for cancer. All proved no better than dummy pills in big studies funded by the National Center for Complementary and Alternative Medicine. The lone exception: ginger capsules may help chemotherapy nausea.

As for therapies, acupuncture has been shown to help certain conditions, and yoga, massage, meditation and other relaxation methods may relieve symptoms like pain, anxiety and fatigue.

However, the government also is funding studies of purported energy fields, distance healing and other approaches that have little if any biological plausibility or scientific evidence.

CHILDREN with attention-deficit hyperactivity disorder might appear rowdy and indisciplined, but they are actually trying to cope with a faulty perception of time.

What to most of us seems like a short stretch of time would drag unbearably for someone with ADHD, says Katya Rubia of the Institute of Psychiatry at King's College London. Her team's research, reported this week, adds to a growing body of evidence for the importance of time perception in a wide range of psychological disorders.

ADHD affects around 5 per cent of children globally, most of them boys. Studies relating to the disorder have focused on patients' short attention spans and impulsive behaviour. But ADHD is characterised by a shortage of dopamine, which is known to affect time perception, so Rubia and her colleagues wanted to know if this was the source of the kids' problems.